Clean up code style in open()

* Spacing, quotes, line length as per code style guidelines
* Use named argument instead of argument[2]
* Clean up displayLine ternary
jQuery performance fixes, style cleanup in render()

* Spacing, quotes as per style guidelines
* Include tag names in selectors for better jQuery performance
* Use .css() instead of .hide()/.show() (less overhead)
More detailed comment box title for changesets

Include the filename, not just the line number, when commenting on a line in a changeset.
Use a single template for line comments

Instead of using two different templates with a minor difference, use one template with an argument that tells it whether to expand the TH to one column or two.

This uses a templateData attribute on the view; we add an argument to it on initialize() and pass it to the template on render().